Tensiometer



M. HATTAN TENS IOMETER July 31, .1945.

Filed Sept. 13, 1944 1 INVENTOR.

fizz/PK 6547-74 A770 EVJ Patented July 31, 1945 UNITED STATES P ATE N T OFFICE Day on. Ohio Alllhlflllll September 13, 1", 86 N0- 553,85

8 Olalms. 18-1) ,(Granted nnd'erthe act of March 3, 1883, as

amended April 80, 1928: 870 0. G. 75'!) The invention described herein may be manuiactured and used by or iorthe Government for governmental purposes. without the payment'to me oi any royalty thereon.

This invention relates to devices for measuring tension, and more particularly to devices for measuring tension in cables and the like. I

In structures herei'oiore proposed for tensiom. eters, means are provided for clamping short lengths oi a cable or the like, the tension oi which it is desired to measure. the clamping arrangement being such that a deflection is produced within the-length oi cable so clamped. The deable range 0! tensions for any single device.

One of the drawbacks of many prior devices resides in the fact that engagement of the clamp with the cable is on a side or the cable opposite to that engaged by the movable element of the deflection scale so that inaccuracies are introthe measur-- cluded in the clamping means and againstyzhich theicable is secured. In this construction, ditierent thicknesses of cable produce no motion oi the movable element tending to actuate the scale means, thereby eliminating the initial inaccuracies found in prior devices.

It is a, iurthe'r object of my invention to provide my device with a structure whereby iorce applying means such as torque indicating wrenches oi varying ranges may be removably secured thereto for realizing a, wide range of bending moments to produce deflections in cables widely varying in tension values. The tension in a cable may thus be measured by comparison 0! the deflection produced therein with the indicated torque required to produce that degree of deflection. In this manner, a plurality oi torque indicating wrenches oi varying torque indicating ranges may be selectively secured to my device for measuring corresponding ranges of tension. whereby the overall tension measuring range of my device is increased accordingly.

duced when the device is used in conjunction with cables oi varying thickness. A iurther drawback oi prior constructions is the limited range of tensions measurable therewith since in many constructions the iorce used to produce deflection in the cable is nonvariable and. accordingly, the range of tension which can be measured with such devicesialimitedbytheabilityottheiorceto produce a deflection on the scale means within the upper and lower limits thereof. In constructiona where the deflecting iorce is variable, the range or tensions measurable by any, given device is still limited by the limits in variation oi the deflection producing iorce.

It is, therefore. an object of my invention to provide a tensiometer suitable for use with cables oi widely V ing thickness without introducing 'inaceuraciesin the deflection scale reading due tosuohvariaizion.v Iprovidesoalemeanshaving a movable element adapted to meals a cable and clampingmeansadaptedtoclampaportionoi thecabla,thearrangementbei ngsuchthatthe oiamagementoithemovableelementis Other obiects and ieatures or my invention will be apparent irom the detailed description which follows, with reierence to the appended drawing in which:

'I lg. lisaviewoithedeviceshowing themanner of attachment to a cable:

Fig. 2 is a transverse view oi the device showing it in relation to a section taken through the cable; and, V

Fig. 3 is a generally exterior view of the device showing a particular type of torque indicating wrench secured thereto.

With reference to the flgures oi the drawing, a cable I is shown having a short length thereoi secured between a pair of clamping elements com prisingashelisandaplatel. Theshelilia preferably integral with the body i of the device and the plate 4 is movable with relation thereto tor the purpose at clamping various thicknesses oi cables against shelf 3 by means comprising two thumb screws I and I coacting with threads in bodye,andaraisedportion lloithebodylis adapted to provide iulcrum reaction agaiitt plate 4. Ascalelt havingclockwiseand'coimterclockwise indicia its and lib, respectively.

.theretoandcomprising Iact, any suitable zero point regardless of extended to react against. an abutment II on arm II and abutment", respectively. Abutment 22 is formed by welding a lug, or angular shape tobodyl. Thebodyihasdependingtheretrom means i'oriecuringa torque indicating wrench ll a e erally cylindrical member]! having an end recess fl-adapted'to receive the work head end of the/torque indicat-- ing'wrench II of a typeused in conjunction with detachable work heads, such as is disclosed in my copcnding applications Serial Nos. 544.127 and 544,128. The wrench as disclosed in the copentiing applications has a signal lamp adapted to light upon application of a the light being visible through ports 28. whereby an operator is readily apprisedoi a predetermined bending moment having been reached. It is to be understood, however, that the tensiometer herein disclosed is in no way limited to a torque indicating wrench oi the typedescribed, and in torque indicating wrench adapted to removably engage the body member I predetermined torque.

assess:

Preparation or simple tables or graphs to be used in themanner hereinabove regarded as within the mechanical. skill oi persons iamiliar with'thev art and; specific expert mental or calculating procedures are not deemed a necessary part or the disclosure or applicant's invention.

. Another manner or tensions in cables by means or the tensiometer herein disclosed would be to calibrate either the indicia of the torque indicating wrench II or the scale l2 to read directly in tensile units with reference to a selected point or points on the indicia of the other. Further. a plurality oi indicia scales could be provided on the scale is reading directly in tensile units ior use in conjunction with a pinfor providing bending moments to produce deflections in cable I may be utilized. v

A particular feature or the device is the coaction between arm I! and shell I, the arr ment being such that the line 01 engagement Ila of arm It with cable I is'on the same side thereof as the side or the cable engaging shelf 3, whereby, the scale I! having been originally set to read at the zero point with reference to an index mark II on body member s when the engaging line Ila is in alignment with shell I, it will be apparent that the scale will remain at the the thickness of any cable clamped in the device.

In operation, the wrench 2l,,having been inserted in the wrench holding means II, a torque stress is exerted on the wrench in the plane of the cable, a bending moment being thus transmitted through the body member 6 to which the cable is clamped, causing a deflection in the cable. The extent oi deflection is registered on one or the sets of 'indicia Ila or l2b of scale I! with reference to the index mark 30 by virtue of the misalignment of engaging line Ila and the shelf 3. Such misalignment causes the arm II to rotate I the scale I! either clockwise or counterclockwise,

' One such method is to set the torque indicat-.

ing indicia a of wrench 25 so'that the signal means 01 the .wrench will be responsive to a predetermined torque, whereby in conjunction with a previously prepared numerical table, the degree of deflection obtained with this specific torque reading is translated into the amount of tension existing in e cable. Conversely, tension may be measur by deflecting the cable to an arbitrary degree and ascertaining the indicated torque required to produce such deflection, whence reference to a previously prepared numerical table will yield the amount oi tension in the cable. Similarly, graphs may be used instead of numerical tables for the same purpose, there being a suitable number or such graphs or tables available for use with the tensiometer to cover the overall range provided by a plurality of indicating wrenches oi diiierent ranges.

rality of torque indicating wrenches or varying Other variations in the mechanics 0! comparing the deflection oi the cable with the torque producing such deflection are possible and the invention is not limited to the several described.

Having thus described my invcntion. I claim:

1. A tensi'ometer for measuring tension in cable-like members comprising. in combination, a clamp adapted to be clamped to a length of cable and deflection scale means associated therewith and having a movable member adapted to engage said cable, and a torque indicating wrench means adapted to exert a bending moment on said cable through bodily motion or said clamp to cause deflection oi said cable, whereby the deflection at said cable is resistered on said scale means and whereby the tension in said cable is measurable by comparison of the indicated torque producing said bending moment and the deflection registered on said scale means.

2. In a tensiometer as set forth in claim 1, including means for removably securing said torque indicating wrench means to said clamping means, whereby bending moment is exerted therethrough and whereby torque indicating wrench means 0! varying torque indicating ranges may be selectively secured to said clamping means for measuring corresponding ranges of tension.

3. A tensiometer for measuring tension in cable-like members comprising, in combination, a device adapted to be clamped to a length of cable and including deflection scale means pivotally associated therewith and having an arm adapted to engage said cable, and a torque indicating wrench means having torque indicating indicia readable thereon and operativelyconnected to said device to exert a bending moment on said cable through bodily motion of said device, whereby the deflection in said cable is operative to cause motion of said arm to register the degree of deflection on said scale means for the purpose of measuring tension in said cable by comparison of the degree or deflection therein with the indicated reading of said torque indicating means corresponding to the degree of bending moment exerted on said cable.

4. Ina tensiometer for measuring tension in cable-like members, clamp means adapted to be clamped to 1 length or cable, a scale pivotally associated with said clamp means and an arm provided on said scale and adapted to extend into engagement with said cable at a point beyond said clamped length, an index mark on said clamp means for coaction with indicia of said scale, a torque indicating wrench means operatively connected to said clamp means to exert a bending moment on said cable through bodily motion of said clamp means, the deflection oi said cable ,due to bending moment being operative through engagement of said cable with said arm to deflect said scale relative to said index mark, whereby the tension in said cable is measurable by comparison of the degree of deflection registered on said scale and the indicated torque of said torque indicating means corresponding to the bending moment exerted on said cable through said clamp means.

5. In a tensiometer as set forth in claim 4, including means adapting said torque indicating wrench means to be removably associated with said clamp means, whereby a plurality of torque indicating wrench means of varying ranges of torque indication may be selectively associated .with said clamp means for measuring corresponding ranges of tension.

6. In a tensiometer for measuring tension in cable-like members, a body member comprising .a relatively fixed shelf means adapted to abut a length of cable on one side of the surface thereof,

' and means on said body member for clamping said length of cable against said fixed shelf means,

surface of said cable abutting said shell means,

' sald scale means having a zero setting with reference to an index mark on said body member when said clamped length of said cable is in alignment with the point of engagement of said lever means, and torque indicating wrench means operatively connected to said body member to exert a bending moment on said cable to misalign said clamped length of cable and said point of engagement of said lever means, whereby the extent of said misalignment is reglsterable on said scale means and the tension in said cable measurable by said registered extent of misalignment with reference to the indicated torque of said torque indicating wrench means corresponding to the bending moment exerted on said cable.

7. In a tensiometer as set forth in claim 6, including means adapted to removably secure said torque indicating wrench means to said body member, whereby a plurality of torque indicating wrench means of varying torque indicating ranges may be selectively secured to said body member to measure corresponding ranges of tension.

8. In a tensiometer as set forth in claim 6 wherein said scale means has indicia extending on opposite sides of said index mark for registering the extent of misalignment in said cable caused by clockwise or counterclockwise bending moments.

MARK HA'I'IAN. 

